Problem: The Carter Center has been combating Guinea worm disease (GWD) for nearly three decades. What factor has recently complicated eradication efforts? Dogs can also act as host to the same species of Guinea worm that affects humans. Copepods that host Guinea worm larvae have become resistant to all pesticides. Abate, the pesticide used to prevent GWD, is no longer being manufactured. The Carter Center has run out of funds to continue fighting GWD. Cases of Guinea worm disease (GWD) have dropped dramatically in humans but are increasing in dogs. Researchers note that these numbers tend to increase when GWD eradication efforts in humans make progress. Why this happens is not understood.